1. Technical Field
The subject matter of the present disclosure broadly relates to the art of tires and, more specifically, to a tire including a tread having a pattern of tread elements disposed in a noise-reducing pitch sequence.
2. Background Information
The subject matter of the present disclosure may find particular application and use in association with pneumatic tires used on agricultural equipment (e.g., tractors, combines and harvesters) or otherwise in association with agricultural-related applications, and is illustrated and described herein with specific reference to such agricultural applications. It is to be understood, however, that the subject matter of the present disclosure is broadly applicable to non-pneumatic tires (e.g., solid rubber tires) and is also suitable for inclusion on tires used in association with one or more of a wide variety of other applications (e.g., ATV, construction and forestry applications). As such, the specific reference herein to pneumatic tires for use in agricultural applications is merely exemplary and not intended to be limiting.
Farm equipment, such as tractors, combines and harvesters, for example, are traveling increasing distances over road surfaces during travel between agricultural sites. In an effort to decrease the percentage of time spent in transit, farm equipment is becoming increasingly capable of high-speed travel along roadways (e.g., travel at speeds exceeding 40 MPH). Due to these and/or other circumstances, noise and vibration levels generated by conventional tires on such agricultural and/or other off-road vehicles during travel along roadways and at these higher speeds are becoming increasingly problematic.
Traditionally, agricultural and other tires intended primarily for off-road use have been designed with an emphasis on performance during intended use. For example, agricultural tires may be designed with a focus on draw-bar traction properties, tread-to-void ratios for cleaning and/or soil penetration characteristics, as well as the geometric configurations that promote tire life and durability.
For example, one tread characteristic that is commonly associated with traction and wheel slippage properties relates to the rigidity of the tread elements that form the tread of the tire. More specifically, the rigidity of the tread elements will normally have a relation to the geometric configuration (i.e., the size and shape) of the tread elements. As such, variations in size and/or shape of adjacent tread elements can result in corresponding variations in rigidity that could undesirably affect traction and wheel slippage performance. As a result, many agricultural and other off-road tire designs utilize a mono-pitch tread pattern in which each tread element is identical to the next tread element around the circumference of the tread pattern.
The use of a tread pattern for a tire that includes a pre-determined pitch sequence for aiding in the reduction of noise and/or vibration generated by the tire tread during use is, in general, well known. One example of agricultural tire having such a pre-determined pitch sequence is disclosed in WO/2011/093856 published Aug. 4, 2011 (US20130042952A1). This publication discloses a pitch sequence for a forty-four pitch tire in the arrangement of 22222111121212111222211111222121122211112111 wherein the 1 represents the twenty-four shorter pitches and the 2 represents the twenty longer pitches.
One existing tire is a 500/70R24 having a pitch count of 40, an outside diameter of 51.2 inches, an arc of 17.7 inches, a foot print length (FPL) of 13.8 inches, and a footprint ratio (FPR) of 90. There is a desire to modify this tire to have increased dimensions and thus a desire to develop a pitch sequence that aides in the reduction of noise for the revised tire while providing the desired performance characteristics commonly associated with tires used in agricultural and other off-road applications.